1. Technical Field
The present disclosure relates to a display device and a light adjusting method thereof, in particular, to a display device and a light adjusting method thereof for adjusting the threshold voltage of the driver transistor.
2. Description of Related Art
Display device for displaying images has been widely used in manufacturing and daily life along with widespread of the multimedia apparatus such as computer, cell phone and television. In a typical Organic Light Emitting Diode (OLED) display device, multiple transistors are utilized to control and drive light emitting diode to have each associated light emitting diode generating proper brightness.
For instance, FIG. 1 shows a schematic diagram illustrating a conventional OLED display device. As shown in FIG. 1, the display device 9 has a switching transistor 90, a capacitor 92, a driver transistor 94, and a light emitting diode 96. The switching transistor 90 being controlled by a scan line SCAN selectively stores the gray scale voltage transmitted by a data line DATA into the capacitor 92 to adjust the driving current outputted by the driver transistor. However, different semiconductors manufactured by same factory may contain discrepancies in the characteristics (e.g., the threshold voltage) thereof. In other words, for same gray scale voltage applied to the driver transistors 94, the driving current outputted may vary.
In view of displayed image, the discrepancies in the driving current may cause mura in brightness of the image thereby affecting user's viewing quality. In order to overcome issue of mura, an addition circuitry is added to each pixel to compensate the difference in the driving current. However, it is known that extra circuitry structure may reduce the opening ratio of pixels. Hence, a new display device is required by the industry with the new display device being capable of adjusting the brightness uniformity of the display imaged without adding new circuit structure in each pixel.